&bgr;‐PdAl was studied as a Schottky contact to metalorganic chemical vapor deposition grown In0.52Al0.48As. Intermetallic alloy &bgr;‐PdAl was chosen in order to utilize the Al–In exchange reaction which may occur between PdAl and In0.52Al0.48As, which would result in an enhanced Schottky barrier height.I–V,C–V, and deep level transient spectroscopy (DLTS) were used to determine the contact characteristics. The contact barrier height (&fgr;b) was measured byI–VandC–Vmethods after different annealing conditions, and good agreement betweenI–VandC–Vresults were obtained. The largest &fgr;bvalue is 0.67 eV fromI–Vmeasurement (0.69 eV fromC–V) after the diode was annealed at 450 °C for 1 min. DLTS measurements were carried out to examine the effect of deep traps in the In0.52Al0.48As layer. Two deep levels were found, but the concentrations are lower than the intrinsic donor concentration obtained from the Hall method. The activation energies for these two deep levels obtained from an Arrhenius plot are 0.38 and 0.65 eV, respectively. ©1995 American Institute of Physics.